Daily Cosmetic Research Analysis
Three studies advance cosmetic science and practice: an OECD Guideline 497-based non-animal defined approach accurately classified skin sensitization risk for fragrance ingredients; a PROSPERO-registered systematic review found carbamide peroxide gels yield greater color change with comparable shade change and potentially less sensitivity than hydrogen peroxide; and a population study linked adverse childhood experiences to higher cosmetic surgery uptake and dissatisfaction, especially among non
Summary
Three studies advance cosmetic science and practice: an OECD Guideline 497-based non-animal defined approach accurately classified skin sensitization risk for fragrance ingredients; a PROSPERO-registered systematic review found carbamide peroxide gels yield greater color change with comparable shade change and potentially less sensitivity than hydrogen peroxide; and a population study linked adverse childhood experiences to higher cosmetic surgery uptake and dissatisfaction, especially among non-heterosexual men.
Research Themes
- Non-animal safety assessment for cosmetic ingredients
- Effectiveness and tolerability of cosmetic dental bleaching
- Psychosocial determinants and outcomes in aesthetic surgery
Selected Articles
1. Case study on the evaluation of skin sensitization for 23 selected fragrance ingredients using a defined approach based on OECD Guideline 497.
Using OECD Guideline 497-ITSv2, an integrated defined approach combining QSAR, DPRA, and h-CLAT classified 23 fragrance ingredients: 17 as sensitizers, 5 inconclusive, and citronellol not classified; classifications aligned with LLNA patterns. The work supports adopting non-animal test batteries for robust cosmetic ingredient sensitization assessment.
Impact: Strengthens regulatory-grade, animal-free safety assessment for cosmetics by demonstrating concordance of a defined approach with LLNA across multiple fragrance allergens.
Clinical Implications: Supports integrating non-animal defined approaches into pre-market safety assessments to reduce allergic contact dermatitis risk from fragrances and guide ingredient selection.
Key Findings
- Integrated DA (QSAR + DPRA + h-CLAT) classified 17/23 substances as sensitizers, 5 inconclusive, and citronellol as not classified.
- DA classifications showed similar patterns to LLNA outcomes, supporting external validity.
- Results emphasize combining in silico, in chemico, and in vitro data to improve accuracy of sensitization assessment.
Methodological Strengths
- Use of OECD Guideline 497 ITSv2 standardized defined approach integrating multiple orthogonal assays.
- Benchmarking against LLNA provided cross-method concordance.
Limitations
- Regulatory validation pending; five substances remained inconclusive.
- Limited to 23 ingredients without human clinical patch-test confirmation.
Future Directions: Expand chemical coverage, harmonize thresholds, and prospectively validate against human patch test databases to refine predictive performance.
Twenty-three single-ingredient substances, selected from materials labeled as allergens in cosmetic fragrances, were assessed for skin sensitization potential using a defined approach (DA) based on the OECD Guideline 497 Integrated Testing Strategy version 2 (ITSv2). According to the ITSv2, skin hypersensitivity data for these selected substances were integrated. In chemico data (from the Direct Peptide Reactivity Assay, DPRA) and in vitro data (from the human Cell Line Activation Test, h-CLAT) were obtained from existing databases, while in silico data were generated via the automated workflow of the OECD QSAR Toolbox. The DA for skin sensitization, which combines QSAR predictions with DPRA and h-CLAT test results, categorized 17 substances, including 2-benzylideneheptanal, as "Sensitizers"; 5 substances, including 4-methoxybenzyl alcohol, as "Inconclusive"; and citronellol alone was categorized as "Not Classified." The outcomes from the Local Lymph Node Assay (LLNA) for substances identified as skin sensitizers by the DA method demonstrated similar classification patterns to those from DA. These results underscore the necessity of integrating comprehensive in vitro, in chemico, and in silico data for accurate evaluation of potential skin sensitizers. This case study could aid in enhancing the safety assessments of potential skin sensitizers using DA; however, final categorization is subject to validation by regulatory authorities.
2. Comparative efficacy of external dental bleaching gels: a systematic review of whitening performance and longevity.
This PROSPERO-registered systematic review indicates carbamide peroxide gels achieve greater color difference (ΔE) than hydrogen peroxide gels with similar shade guide changes (ΔSGU). Higher-concentration carbamide peroxide was associated with less tooth sensitivity than higher-concentration hydrogen peroxide, with overall moderate-quality evidence.
Impact: Synthesizes current evidence to guide product selection and patient counseling in cosmetic dentistry, leveraging standardized color metrics and registered methodology.
Clinical Implications: Clinicians may preferentially select carbamide peroxide gels for greater ΔE with similar ΔSGU and potentially lower sensitivity at higher concentrations; standardize outcome measurements and counsel on sensitivity mitigation.
Key Findings
- Carbamide peroxide gels outperformed hydrogen peroxide gels on ΔE, while ΔSGU was comparable between agents.
- Higher-concentration carbamide peroxide was associated with less tooth sensitivity than higher-concentration hydrogen peroxide.
- Evidence quality for ΔE and tooth sensitivity was graded as moderate across whitening agents.
Methodological Strengths
- PROSPERO-registered protocol with multi-database search and PRISMA-aligned methods.
- Use of objective colorimetric outcomes (ΔE) and clinical shade metrics (SGU).
Limitations
- Heterogeneity in gel concentrations, application protocols, and follow-up limits meta-analytic synthesis.
- Limited long-term durability data and incomplete reporting in some studies.
Future Directions: Conduct head-to-head RCTs with standardized concentrations, application protocols, long-term follow-up, and patient-reported sensitivity outcomes.
OBJECTIVES: A standard cosmetic dentistry procedure that is designed to improve the appearance of stained teeth is external dental whitening. Age, dietary choices, cigarette usage, or teeth trauma are among some of the causes of teeth discoloration. The objective of this study is to study the effects of whitening gels on teeth color, duration of effects, and potential adverse effects. METHODS: To find studies that satisfied the inclusion criteria, two independent reviewers searched electronic sources, including PubMed, Scopus, Web of Science, and the Cochrane Library, in July 2024, which was updated on August 1, 2024. Changes in tooth color before and after external bleaching were the key end measures for the studies that were chosen, and these changes were measured using either shade guide units (SGU) or a spectrophotometer/colorimeter (ΔE). The effectiveness of various bleaching gels was compared after combining the pertinent research in subgroup analysis. These substances comprise gels based on hydrogen peroxide, carbamide peroxide, and other substances frequently applied during teeth whitening procedures. The Cochran Q test and I RESULTS: The results of this systematic review summarize the most recent data on the effectiveness of various bleaching gels used in external teeth whitening. Regarding ΔE, carbamide peroxide gels performed better than hydrogen peroxide-based whitening gels, although their ΔSGU values were comparable. The quality of evidence for ΔE*, risk, and intensity of teeth sensitivity was graded as moderate in all types of whitening agents. CONCLUSION: Teeth that are stained can be significantly bleached by whitening gels such as hydrogen peroxide and carbamide peroxide. The greater concentration carbamide peroxide bleaching gel showed less tooth sensitivity than the higher concentration HP bleaching gel. TRIAL REGISTRATION: This study protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO) dated November 26, 2023, with the registration ID CRD42023483434.
3. Associations Between Adverse Childhood Experiences and Cosmetic Surgery: Effect Modification by Sexual Orientation.
In a nationwide Japanese survey (n=27,824), having ≥4 adverse childhood experiences was associated with nearly threefold higher odds of undergoing cosmetic surgery and higher odds of dissatisfaction. The association was markedly stronger among non-heterosexual men (OR 14.60), indicating important effect modification by sexual orientation.
Impact: Identifies a large, psychosocial risk factor for cosmetic surgery uptake and dissatisfaction, highlighting the need for preoperative psychosocial screening and tailored counseling.
Clinical Implications: Incorporate ACEs screening and sexual orientation–sensitive assessment into aesthetic surgery consultations; consider mental health referrals, expectation management, and shared decision-making for high-risk groups.
Key Findings
- Participants with ≥4 ACEs had higher odds of undergoing cosmetic surgery (adjusted OR 2.97, 95% CI 2.51-3.51).
- Effect modification: non-heterosexual men showed markedly stronger association (OR 14.60, 95% CI 8.49-25.11).
- ≥4 ACEs were associated with greater dissatisfaction with cosmetic surgery outcomes (OR 1.92, 95% CI 1.36-2.71).
Methodological Strengths
- Large sample size with multivariable logistic regression and interaction terms.
- Stratified analyses by sexual orientation and adjustment for sociodemographic factors.
Limitations
- Cross-sectional, self-reported data limit causal inference and may introduce recall or selection bias.
- Internet survey without clinical verification of procedures or outcomes; residual confounding possible.
Future Directions: Prospective cohort studies and interventional trials of preoperative psychosocial screening to assess causal pathways and improve outcomes among sexual minority men.
BACKGROUND: Few studies have investigated the impact of adverse childhood experiences (ACEs) on undergoing cosmetic surgery. Additionally, the association may differ by sexual orientation. This study aimed to identify the association between ACEs and undergoing cosmetic surgery, with analyses stratified by sexual orientation. METHODS: We analyzed responses from 27,824 participants aged 18-79 years from the 2023 Japan COVID-19 and Society Internet Survey. The participants reported ACEs, their cosmetic surgery experiences, and sociodemographic information. We used multivariate logistic regression analysis to examine the associations between ACEs and cosmetic surgery, including interaction terms with sexual orientation. RESULTS: Individuals with 4+ ACEs were 2.97 times more likely to undergo cosmetic surgery (95% confidence interval [CI] 2.51-3.51) after adjusting for sociodemographic status. This association was stronger among non-heterosexual men (OR: 14.60, 95% CI 8.49-25.11, p < 0.001). Participants with 4+ ACEs were also more likely to report dissatisfaction with cosmetic surgery outcomes (OR: 1.92, 95% CI 1.36-2.71, p < 0.001). CONCLUSIONS: Individuals with four or more ACEs were more likely to undergo cosmetic surgery, especially non-heterosexual males. In addition, participants with four or more ACEs were more likely to be dissatisfied with the surgical outcomes. These findings highlight the importance of considering psychosocial history, including ACEs, in cosmetic surgical assessment and patient care. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .